I mean or I think?

English: What do I think about Scottish independence?Czenglish: Yes, what’s the difference?

When giving an opinion you can use ‘think’ at any time in the conversation, including at the start. ‘Mean’ is used to clarify a point you have already made, so you can’t start giving or asking for an opinion with ‘mean’.

For example:
– What do you think about Scottish independence?
– I think it will depend on Brexit.
– In what way?
– I mean, if Brexit is a disaster, Scottish independence will be much more likely.